End flap closing means for cartons



Jan. 8, 1963 R. o. woELFER 3,071,910

END FLAP CLOSING MEANS FOR cARToNs Filed Feb. l, 1961 2 Sheets-Sheet 1 s \\i d l ATTORNEY Jan. 8, 1963 R. o@ WOELFER END FLAP CLOSING MEANS FOR cARToNs 2 Sheets-Sheet 2 Filed Feb. 1, 1961 INVENTOR ROBERT O. WOELFER ATTORNEY United States -Patent dice 3,071,910 Patented 'Jr-1n. 8, 1963 3,071,910 END FLAI CLOSING MEANS FOR CARTNS Robert O. Woelfer, 17 Roosevelt Blvd., Railway, NJ.

Filed Feb. 1, 1961, Ser. No. 86,366 Claims. (Cl. 53--376) The invention relates to packaging, and is more particularly directed to improvements in apparatus for closing cartons.

The packaging of articles in cartons customarily involves setting up the cartons and conveying them past suitable folding and tuck-in means to close the end or ends of each carton after the article to be packaged has been inserted in the carton. Where the carton has two ends to be closed, the article is usually inserted after one end of the set-up carton is first closed.

Closing the ends of cartons with automatic machinery requires the end panel of each carton to be turned up from the botom toward the top panel and insertion of the closing end flap, which is connected to the endpanel, lbeneath the top panel. Where the carton has a substantial dimension or length in the direction in which it is conveyed on the machine, the top panel has a tendency to sag so that the top panel is closer to the bottom panel midway of its length than where it is connected to the side panels. Also, in order to minimize cost, the carton stock or board of which the carton is fabricated is kept as thin as possible, thereby 'reducing the stiffness of the cartons walls or panels and further increasing the extent of sag of the top panel. As a result, when the closing end flap is bent up for insertion under the top panel by the equipment of the prior art, the edge of the sagging top panel blocks and prevents the insertion of the closing end flap. The failure of the prior art equipment to properly close the cartons as they are conveyed through the machine has required manual effort to correct the inadequacy of the machine, thereby increasing the cost of packaging.

An object of the invention is to provide means for automatically eliminating the sag in the top panel of a carton to thereby assure the proper insertion of the closing end tlap.

Another object of the invention is to provide means automatically responsive to the movement of the carton itself for eliminating the sag in the top panel to thereby assure the insertion of the closing end panel, such means further acting to guide the closing end panel for insertion `beneath the top panel.

Still another object of the invention is to provide means for automatically inserting the closing end flaps of a continuously moving line of cartons in which the top panels, for reasons of linear dimension or thinness of carton stock or both, have a tendency to sag, this being accomplished without interruption of the continuously moving cartons; land it is a further object of the inven- `tion to provide such means of a simple construction which is readily adaptable for association with existing conventional carton closing equipment.

These, and other objects and advantages of the invention will be 4apparent from the following detailed descrip- FIG. 4 is a transverse section, on an enlarged scale, taken approximately in the plane of line 4-4 of FIG. 1;

FIG. 5 is a perspective View illustrating the manner of operation of the closing end llap insertion means of the invention, this view omitting the showing of the adjacent trough and the contained product for the purpose of clarity in illustrationgand FIG. 6 is a top plan view illustrating an end-closing wedge which may be used in conjunction with the closing end ilap insertion means of the invention.

Referring to FIG. 1 which shows the general organization of the v-arious means with which the closing end flap insertion means of the invention is associated, the packaging machine comprises conveyer means A which serves to continuously move the cartons B in the direction of the 4arrow C past an end closing station D. Before reaching the end closing station, the cartons are moved continuously past a loading station E, where an article F, such as a pie or any oth-er product, is inserted by the operator into each carton through an open end thereof.

As may be observed from FIG. 5, the top panel 10 of each of the cartons B sags, because the carton stock is not sufficiently stiff to maintain the panel in a straight or level plane. Such lack .of stiffness may be due to the .relatively large dimension between the cartons side walls or panels 12 and 14, or in the interest of reducing carton cost, the carton stock may be thinner than adequate to furnish the desired stiffness. For convenience of description, the side panel 12 will hereinafter be referred to as the leading side panel and the side panel 14 as the trailing side panel, such designations being related to the positions of the side panels of a carton as it is conveyed through the machine. Each carton also has a bottom panel 18. An end panel 16 is connected to the bottom panel by a fold line, and is adapted to be turned up from the bottom panel to the top panel. As is also common in the art, a closing end flap 20, which is connected to the end panel 16 by a fold line, is to be inserted or tucked in under the top panel 10. The end panel and closing end flap on the other side of the carton are designated 16 and 20', respectively.

In the immediate vicinity of the side panels 12 and 14, and due to the support they provide for the top panel, the top panel is at an elevation or level permitting the vclosing end ap 20 (or 20') to be tucked beneath the `panel leveling means G, to be subsequently described in detail, is provided.

In greater detail, and as shown in FIG. l, the conveyor A includes a pair of parallel endless bands 22 and 22 which are driven continuously over any suitable pulleys or sprockets and by any suitable drive means or motor (not shown) so that the upper horizontal runs, fragmentarily shown in FIG. l, move continuously in the direction of arrow C. The conveyor means A also includes a number of pusher blocks 24 in the form of relatively short angle members extending across and fixed to the bands 22 and 22 in any suitable way. The pusher blocks are uniformly spaced along the conveyor bands, with the distance between blocks somewhat greater than the dimension of each carton in their direction of movement, as indicated in FIGS. 1 and 5.

The machine includes a pair of stationary, elongated, horizontally extending plates located in a common plane and forming the supports 26 and 28. The supports 26 and 28 are parallel and laterally spaced from each other, and the blocks 24 extend from the conveyor bands 22 and 22 up through the space between these supports. Each carton B bridges the space between the supports, and the ends of the bottom panel 18 of each carton rest upon and slide along the upper faces of the supports, shown in FIGS. 2, 3 and 4. Thus, the pusher blocks slidably move the cartons B continuously along the supports in the direction of arrow C.

In the example illustrated in the drawings, both ends of each carton B are open as the cartons approach the loading station E, and the machine operates in the same way on both ends of the carton. It is to be understood, however, that the invention is equally applicable to cartons which have only one open end which must be closed by the machine.

A pair of prebreakers 30 and 32 are xed to and eX- tend longitudinally along the supports 26 and 28, respectively. Each prebreaker is in the form of an elongated channel fixed at one side to the upper face of the support which carries it and has an inner concave face directed toward the support, as shown in FIG. 2. The prebreakers support a plurality of brackets 34, 34 which are distributed along the prebreakers, the brackets in turn respectively Supporting the anvils 36 and 38. The anvils are, for part of their length, elongated angle members having the cross-section shown in FIG. 2 and they are located to extend along and cooperate with the prebreakers. The brackets 34 support the anvils at an elevation so that their undersides 35, 35 are parallel to and spaced above the upper faces of the supports 26 and 28. The end panels 16 and 16 of each carton B are contined for sliding between the anvils and the supports. Thus, before the end panels of each carton are turned up toward the top panel, the anvils maintain the end panels on the supports in the plane of the bottom panel 1S of each carton.

As shown in FIG. 1, the left free ends 40 and 42 of the vertical walls of the anvils 36 and 38, respectively are curved away from the conveyor means A. Opposite ends of the leading side panel 12 of each carton are provided with short inner flaps 44 and 44', and the ends of the trailing side panel 14 of each carton are provided with short inner aps 46 and 46. The anvil 36 and prebreaker 30 extend to the left forward of the loading station E so that before the cartons reach the loading station, the inner flap 44' of Veach carton is engaged by the curved Vend 40 of the anvil 36 and turned over the end panel 16 into the opening between the top and bottom panels. The anvil 36 then maintains the flap 44 folded perpendicularly lto the leadingside panel 12. Just forward of the anvils .curved end 40, the support 26 carries a ipper 48 of a type .well known in the art. The rotary arm 50 of the flipper is driven in any convenient way so that it rotates `tons are synchronized or timed so that the arm does not engage inner aps 44', but does engage and turn in the inner aps 46. Moreover, the flipper arm engages an upperpart of the short inner flap 46', and does not engage the closing end flap 20 of each carton.

As shown in FIG. 2, as each carton moves beyond the flipper 48 toward loading station E, its end panel 16 slides beneath the anvil 36, and the prebreaker 30 operates to turn the closing end ap 20 around the sharp edge provided by the free edge of the horizontal wall of the anvil 36 along a fold line provided between the end panel and closing end ap. Each carton end sliding along the support 26 is in this condition as the carton is conveyed past loading station E. The opposite end of the carton sliding on the support 28 has not yet reached anvil 38 and associated prebreaker 32 so that the operator may slip an article F into each carton through such opposite open end.

As each carton B moves beyond the loading station E its end on support 28 is acted on by the anvil 38 and prebreaker 32 as well as by flipper 48 and its arm 56 in the same manner as described above in connection with the end of the carton on support 26, so that the carton is now in the same or symmetrical condition as shown in FIG. 2. The arm 50 turns in a clockwise direction, as viewed in FIG. 1. Thus, the short inner flaps 44 and 46 also are folded in and slide along the inner surface of the vertical wall of anvil 38, while the closing end ilap 2t) is folded at the fold line between end panel and Hap at the free edge of the horizontal wall of the anvil.

As shown in FIG. 1, the horizontal bottom walls of the anvils 36 and 38 terminate in laterally aligned ends 52 and 52. Beyond these ends the side walls of the anvils are tapered (FIG. 3), and then terminate just ahead of the end closing station D. At the ends 52 and 52' of the anvils bottom walls, the prebreakers terminate and troughs 54 and 54' commence, the troughs forming extensions of the prebreakers. The troughs have a larger radius of curvature than the prebreakers and have upper edge portions 56 and 56 which are located quite close to the top panels of the passing cartons. As shown in FIGS. 3 and 4, the undersides of these upper edge portions are located in substantially the same plane or slightly above the plane of the undersides of the top panels of the movying cartons when the top panels are level or flat. At the end closing station D, the troughs S4 and 54 are provided with slots S8 and 58', respectively, extending horizontally therethrough.

Within the troughs 54 and 54 and beneath the slots 58 and 58', the supports 28 and 26, respectively, carry means in the form of wedges 60 and 60' for turning the end panels 16 and 16 up to the top panel of each carton and to insert the closing end aps 20 and 20' beneath the top panel. The wedges 60 and 60 are xed to and extend longitudinally along the upper faces of the supports 28 and 26, respectively. As shown in FIGS. 4 and 5, the wedges each have inclined upper faces 62 and 62 which rise upwardly from the surfaces of the supports 28 and 26 in the direction of movement of the cartons so that the end panels 16 and 16 of each carton ride up on the edges and are turned in toward the top panel. The upper edge portions 56 and 56 of the troughs form parts of the closing end ilap inturning means in that they direct the closing end laps 20 and 26 to the underside of the top panel 10 of each carton as the closing end flaps turn with the end panels. As shown in FIG. 6, each wedge is inwardly bent to provide an elongated free end which completes the end closing operation. The corresponding free end 64 of the wedge 60 may be seen in FIG. 1.

As shown in FIGS. l and 5, a pair of posts 66 and 66 are xedly carried by the supports 28 and 26, respectively. Each post forms a support means for a pivotally mounted blade of each means G for assuring the insertion of the end ap. The posts 66 and 66 are located at the end closing station D outside of and adjacent the troughs 54 and 54', respectively, and carry at their upper ends pivot pins 68 and 68 which extend freely through respective openings in blades 70 and 70. The blades each extend through the aforementioned slots 58 and 58', and are angled to extend in the direction of movement of the cartons. The blades are in the form of thin, flat plates; they are supported by the posts to lie in a fixed horizontal plane and in a plane immediately below the undersides of the top panels, when the top panels are flat. The blades are movable in their respective slots with respect to the troughs 54 and 54'. The blades are located immediately adjacent the undersides of the upper edge portions 56 and 56 of the troughs.

The blades 70 and 70' are shown in FIG. 1 in their rest positions. They are resiliently urged to such position by yieldable means, preferably in the form of the respective coiled springs 72 and l72. These springs are light in strength `and are respectively iixed to pins 74 and 74' carried by the blades and to pins 76 and 76 carried by the troughs.- The blades are mounted on their posts so that in their rest positions each blades free end 78 and 78' is located in the path of movement of the leading side panel l2 of each carton.

As each carton B moves past the ,end closing station D, its leading side panel 112 engages the blades free ends 78 and 78', turning the blades outwardly in opposition to the springs 72 and 72. As soon as the leading side panel 12 pushes the free end of each blade beyond its lateral edge, the spring for each blade returns the blade to its rest position and Within the carton. Since the sagging top panel lill is supported by and has its highest elevation immediately adjacent the side panels 12 and =14, the ends 718 and 7S of the blades move into the carton and beneath the top panel immediately adjacent the inner surface of the leading side panel 12. As each carton continues to move past the blades, the blades, which are pivotally mounted to swing in a xed horizontal plane, raise the sagging top panel to the level which the top panel has immediately adjacent the side panels 12 Iand 14. At the same time, the closing end ilaps are moved in under the blades by the Wedges dil and dit', the blades acting to guide the closing end flaps into the carton and under the top panel, as shown in FIGS. 4 and 5. When the trailing side panel 14 of the continuously moving carton reaches the blades, the blades. are swung outwardly by such supported panel, and they then snap back into the space ahead of the next carton to be engaged by the leading side panel 12 thereof to repeat the above operation. Thus, each blade 70 and 7 0 responds automatically to the movement of the cartons themselves to level out the sagging top panels to insure that the closing end rilaps are properly inserted. Although it is not essential, the short inner llaps `44, 44', 46, 46 may be cut away at their upper edges, as indicated for the flap 46 in lElG. 5.

As shown in FIG. l, and if desired, closing of the cartons ends may be completed by providing rollers 80 and 80 which are supported for rotation by the bell cranks 82 and 82'. The bell cranks are pivotally mounted on the supports 28 and 26, respectively, and resiliently urged by springs 84 and 84 to hold the rollers against the end panels 16 and 16 of the continuously moving carton.

lf desired, the posts 66 and 66 may be made adjustable in height so that the blades 70 and 70 can be used with troughs having slots at different elevations t-o be adapted for use with cartons of different height or distance between top and bottom panels. Also, although the springs i2 and 72." and the mounting thereof shown in the drawings and described above is preferred, other forms of yieldable means may be used. For example, these springs may be replaced by wire springs coiled around the pivot pins 68 and 68', bearing at one end against the blades, and having their other ends stationary. Furthermore, other suitable configurations may be used instead of the preferred blade control shown in the drawing. These, and other changes will be apparent from the foregoing detailed description, and such changes are Contemplated within the spirit and scope of the invention as sought to be defined in the following claims.

I claim:

l. in apparatus for closing an end of a carton hav-ing top and bottom panels, side panels, an end panel adapted to be turned up from said bottom to said top panel, and wherein a closing end llap is connected to the end panel for insertion beneath said top panel, means for continuously moving the carton past an end closing station, and means at said station responsive to engagement by the carton for Imaintaining the portion of the top panel intermediate the iside panels at the elevation of the portions `of the top panel immediately adjacent the side panels, whereby the top panel c-annot sag to interfere with the insertion of the closing end flap beneath the top panel.

2. In apparatus for closing an end `of a canton having top :and bottom panels, side panels, an end panel `adapted to `be turned up from said bottom to said top panel, and wherein -a closing end flap is connected to the end panel for insertion beneath the Itop panel, means for continuously moving the carton past an end closing station, means at said s'tation for moving the end panel up to and the closing end flap beneath the top panel while the carton continues to move past the station, and means at said station responsive to engagement by the carton for maintaining the portion of the top panel intermediate the side panels at the elevation of the port-ions of 'the top panel immediately adjacent the side panels, whereby the top panel cannot sag to interfere with the insertion of the closing end flap beneath the top panel.

3. In apparatus for closing an end of a carton having a sagging top panel, means for continuously moving the carton pas-t .an end closing station, and blade means at said station responsive to engagement by the carton for supporting the top panel `at an elevation to eliminate the sag therefrom as the canton moves past said station.

4. In apparatus for closing an end of :a carton having a sagging top panel, la bott-om panel, side panels, an end panel adapted to be turned up from said bottom to said top panel, and wherein -a closing end flap is connected to the end panel for insertion beneath the top panel, means for continuously moving the carlton past an end closing station, means at said station for moving the end panel up to and the closing end flap beneath the top panel while the carton moves past said station, and blade means at said station automatically responsive to engagement by the carton for supporting the top panel at an elevation to eliminate the sag therefrom as the carton moves past said station.

5. In apparatus for closing an end of a carton having rtop and bottom panels, side panels, an end panel adapted to be turned up from the bottom -to the top panel, and wherein a closing end ap is connected to the end panel for insertion beneath the top panel, conveyer means for continuously moving a plurality of cartons along a given path past an end closing station lwith each car-ton having one side panel leading land the other trailing, a blade, means pivotally supporting the blade at one end thereof for turning movement in a fixed plane |occupied by the underside of each cartons ltop panel when the top panel is flat, said blade extending in the general direction of movement of the cartons along said path with the free end thereof adapted for entry into a cart-on beneath the top panel thereof, and resilient means for yieldably maintaining said yfree end of the blade in the path of movement of the leading side panel for eng-agement 'and movement thereby in oppositionjto said resilient means, said resilient means moving said free end of the blade beneath the top panel when the leading side panel moves beyond the blades free end, whereby the blade supports the top panel at its underside to eliminate sag therein, said blade being turned by engagement with the trailing side panel rto eject the blade from the carton, said resilient means returning the blade for engagement of the free end thereof by the leading side panel of the next carton.

6. In an apparatus as lset forth in claim 5, means at said station for turning the end panel of the moving carton up to the 'top panel and the closing end ap beneath the top panel while the latter is supported by said blade, the blade acting to guide the closing end flap beneath the top panel.

7. Apparatus for closing an end lof a carton having top and bottom panels, side panels, an end panel to be turned up from the bottom to the top panel, and wherein a closing end ap is connected to the end panel for insertion beneath the 'top panel, said apparatus comprising ya support having a surface along which said end panel slides before being turned up, a trough carried by said support for guiding said end panel up to 'and said closing end flap beneath the top panel, said trough being provided with a slot lying in a plane occupied by the underside of the top panel when the top panel is flat, a at blade having a portion thereof extending through the slot, means exterior of the trough for pivotally supporting the blade, and resilient means urging the blade beneath the top panel to engage the understide thereof to eliminate sag in the top panel.

8. Apparatus for closing an end of a carton having top and bottom panels, side panels, an end panel to be 'turned up from the bottom to the ytop panel, and wherein a closing end flap is connected to the end panel for insertion beneath the top panel, said apparatus comprising `a support having a ilat top face, a trough mounted on said face having a longitudinal free edge vspaced from and parallel to said face and a hollow interior directed toward said face, said trough being provided with -a slot adjacent said free edge located in a plane parallel to said face and lying in a plane occupied by the underside of the top panel when the top panel is at, a post carried by said support outside of said trough, a ilat blade pivotally supported by the post and extending through said slot for movement with respect to said trough, and resilient means yieldably maintaining said blade in la predetermined rest position.

9. Apparatus for closing an end of a carton having top and bottom panels, side panels, an end panel adapted to be turned up from the bottom to the top panel, and wherein a closing end ap is `connected to the end panel for insertion beneath the top panel, said apparatus comprising conveyer means for continuously moving a plurality of cartons along a given path past an end closing station with each carton having one side panel leading and the other trailing, a trough in which the end panel and closing end flap of each carton are conned for folding as the cartons move past said station, said trough being provided with a slot lying in a plane occupied by the underside of a carton top panel when the top panel is flat, a dat blade extending through the slot, means exteriorly of the trough pivotally supporting the blade at one end thereof for turning movement in a fixed plane, said blade extending in the general direction of movement of the cartons along said path with the free end thereof adapted for entry into a carton beneath the top panel thereof, and resilient means for yieldably maintaining said free end of `the blade in the path of movement of the leading side panel for engagement and movement thereby in opposition to said resilient means, said resilient means moving said free end of the blade beneath the top panel when the leading side panel moves beyondthe blades free end, whereby the blade supports the top panel at its underside to eliminate sag in the top panel, said blade being turned by Vengagement with the trailing side panel to eject the blade from the carton, said resilient means returning the ing side panel of the next carton.

l0. Apparatus for closing an end of a carton having top and bottom panels, side panels, an end panel adapted to be turned up from the bottom to the top panel, and wherein a closing end ap is connected to the end panel for insertion beneath the top panel, said apparatus comprising conveyer means for continuously conveying a plurality of cartons past an end closing station along a given path with each carton having one side panel leading and the other trailing, a support having a face along which said end panel slides and is located in the same plane as the bottom panel, a trough through which the end panel and closing end flap of each carton are confined for folding as the cartons move past said station, said trough being carried by said face of said support and being provided with a slot lying in a plane occupied by the underside of a top panel when the top panel is flat, an elongated wedge in said trough beneath said slot, said wedge having a top surface rising up from said face of the support in the direction of travel of the cartons, the wedge being located in the path of movement of said end panel for engaging and turning the end panel up to the top panel and cooperating with the trough to direct the closing end flap beneath the top panel, a post carried by said support outside of said trough, a flat blade extending through said slot pivotally supported by the post, said blade extending from the post in the general direction of movement of the cartons along said path with the free end thereof adapted for entry into a carton beneath the top panel thereof, and resilient means for yieldably maintainin said free end of the blade in the path of movement of the leading side panel for engagement and movement thereby in opposition to said resilient means, said resilient means moving said free end of the blade beneath the top panel when the leading side panel moves beyond the blades free end, whereby the blade supports the top panel at its underside to eliminate sag in the top panel, said blade being turned by engagement with the trailing side panel to eject the blade from the carton, said resilient means returning the blade for engagement of the free end thereof by the leading side panel of the next carton.

References Cited in the tile of this patent UNITED STATES PATENTS 1,439,536 Andrews et a1. Dec. 19, 1922 1,724,124 Boileau Aug. 13, i929 2,118,488 Butler May 24, 1938 2,340,835 Malhiot Feb. l, 1944 2,682,210 Bivans .lune 29, 1954 2,685,158 Von Haase Aug. 3, i954 2,844,930 Nelson July 29, 1958 2,948,094 Wells Aug. 9, 1960 

10. APPARATUS FOR CLOSING AN END OF A CARTON HAVING TOP AND BOTTOM PANELS, SIDE PANELS, AN END PANEL ADAPTED TO BE TURNED UP FROM THE BOTTOM TO THE TOP PANEL, AND WHEREIN A CLOSING END FLAP IS CONNECTED TO THE END PANEL FOR INSERTION BENEATH THE TOP PANEL, SAID APPARATUS COMPRISING CONVEYER MEANS FOR CONTINUOUSLY CONVEYING A PLURALITY OF CARTONS PAST AN END CLOSING STATION ALONG A GIVEN PATH WITH EACH CARTON HAVING ONE SIDE PANEL LEADING AND THE OTHER TRAILING, A SUPPORT HAVING A FACE ALONG WHICH SAID END PANEL SLIDES AND IS LOCATED IN THE SAME PLANE AS THE BOTTOM PANEL, A TROUGH THROUGH WHICH THE END PANEL AND CLOSING END FLAP OF EACH CARTON ARE CONFINED FOR FOLDING AS THE CARTONS MOVE PAST SAID STATION, SAID TROUGH BEING CARRIED BY SAID FACE OF SAID SUPPORT AND BEING PROVIDED WITH A SLOT LYING IN A PLANE OCCUPIED BY THE UNDERSIDE OF A TOP PANEL WHEN THE TOP PANEL IS FLAT, AN ELONGATED WEDGE IN SAID TROUGH BENEATH SAID SLOT, SAID WEDGE HAVING A TOP SURFACE RISING UP FROM SAID FACE OF THE SUPPORT IN THE DIRECTION OF TRAVEL OF THE CARTONS, THE WEDGE BEING LOCATED IN THE PATH OF MOVEMENT OF SAID END PANEL FOR ENGAGING AND TURNING THE END PANEL UP TO THE TOP PANEL AND COOPERATING WITH THE TROUGH TO DIRECT THE CLOSING END FLAP BENEATH THE TOP PANEL, A POST CARRIED BY SAID SUPPORT OUTSIDE OF SAID TROUGH, A FLAT BLADE EXTENDING THROUGH SAID SLOT PIVOTALLY SUPPORTED BY THE POST, SAID BLADE EXTENDING FROM THE POST IN THE GENERAL DIRECTION OF MOVEMENT OF THE CARTONS ALONG SAID PATH WITH THE FREE END THEREOF ADAPTED FOR ENTRY INTO A CARTON BENEATH THE TOP PANEL THEREOF, AND RESILIENT MEANS FOR YIELDABLY MAINTAINING SAID FREE END OF THE BLADE IN THE PATH OF MOVEMENT OF THE LEADING SIDE PANEL FOR ENGAGEMENT AND MOVEMENT THEREBY IN OPPOSITION TO SAID RESILIENT MEANS, SAID RESILIENT MEANS MOVING SAID FREE END OF THE BLADE BENEATH THE TOP PANEL WHEN THE LEADING SIDE PANEL MOVES BEYOND THE BLADE''S FREE END, WHEREBY THE BLADE SUPPORTS THE TOP PANEL AT ITS UNDERSIDE TO ELIMINATE SAG IN THE TOP PANEL, SAID BLADE BEING TURNED BY ENGAGEMENT WITH THE TRAILING SIDE PANEL TO EJECT THE BLADE FROM THE CARTON, SAID RESILIENT MEANS RETURNING THE BLADE FOR ENGAGEMENT OF THE FREE END THEREOF BY THE LEADING SIDE PANEL OF THE NEXT CARTON. 